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Just under the wire in 2003...

For $900 you can pick up six 200GB drives, and you can get a RAID 5 controller for under $100.

Yes, any home can have a terabyte disk array for under $1000.

Philo

Philo
Wednesday, December 31, 2003

where?


Wednesday, December 31, 2003

I assume you're referring to IDE 200Gb disks? Can the controller handle all six disks or will you require multiple controllers?

See comments made by others and myself in the IDE RAID thread you started.

Anon
Wednesday, December 31, 2003

What's interesting is that networking is still slow and expensive (in relative terms), so we have a kind of Polynesia effect: islands of data, with a lot of distance between them.

To put it a different way, given those numbers and a bigger budget, you could build some mighty impressive storage for a home business, but how would you actually sell the storage to other people?

Portabella
Wednesday, December 31, 2003

Ack! on the # of drives - you're right, four per channel.

Well then, for $1300 you can get two channels - 1.2TB, or 600GB mirrored.

[I'm insisting on RAID b/c IMHO a TB of data without redundancy is quite simply not a viable solution]

Philo

Philo
Wednesday, December 31, 2003

yeah, I'd guess backing it up to floppies is a little out of the question...
;-)


Wednesday, December 31, 2003

"To put it a different way, given those numbers and a bigger budget, you could build some mighty impressive storage for a home business, but how would you actually sell the storage to other people?"
-------
How to get their data to them?  Take the money you save on the storage array, and spend it on blank CD's and FedEx labels.  :P

John Rose
Wednesday, December 31, 2003

> Take the money you save on the storage array, and spend it on blank CD's and FedEx labels.  :P

I know you're only joking, but in fact Jim Gray (and data pirates too numerous to mention) do recommend FedEx-ing hard disks as the cheapest and fastest way to move large amounts of data around.

Portabella
Wednesday, December 31, 2003

I backed up my terabyte drive on floppies and three days ago it all fell on top of me. I can hardly breath. I've been screaming for hours each day but nobody hears me from my small NY apartment. Thank goodness I fell down near my wireless laptop. At least I can post to joel...

Notorious Packrat
Wednesday, December 31, 2003

"I'm insisting on RAID b/c IMHO a TB of data without redundancy is quite simply not a viable solution"

Redundancy is nice, but seriously what are the odds of a total data loss due to

a) software (i.e. trojan, accidental rm -R, etc)
b) theft

In either case your data is goner. I consider the combined likelihood of a+b to be comparable to losing a drive in a RAID 0 configuration. In other words if you think redundancy is protecting you from data loss, may the gods protect you.

As a sidenote, my data backup strategy has always been to only backup user data -- In the rare event that I had a hardware failure, I'd rather just reinstall everything (always a nice "cleanup" time regardless).

Dennis Forbes
Thursday, January 01, 2004

Agreed that redundancy won't protect you from those two causes, but I wouldn't rank them equally. I'd say the odds of losing a drive are an order of magnitude (perhaps two) greater than the odds of losing data due to misfeasance or accident, esp if you take all the other normal precautions.

Philo

Philo
Thursday, January 01, 2004

Philo can we have your figures?

Hard drive failure on desktops is surprisingly uncommon.  You're talking about a MTBF of millions of hours.

I once asked a guy who was head of IT at a Canadian university with over a thousand IBM's ,and he said he had two hard drive failures in four years. Among the staff computers at our college we've had a couple over the years, and I think we've had a couple in the computer labs.

Robert Moir could no doubt give the figures from his college.

Stephen Jones
Thursday, January 01, 2004

If you value your data, RAID is a must.  Hard disk failure is uncommon, but why risk it?  Given Philo's configuration, it will only set you back the cost of a single hard disk.

If you want protection from accidental or malicious deletion of data, make backups. Simple.

Which is more likely to cause you to lose data? Does it even really matter?  Both are a threat that you can, and should, protect against.

m8v316
Friday, January 02, 2004

I think the argument is that RAID creates its own risk of the controller going.

Moreover the average user should be backing up his data every day, and should have a reasonably up-to-date Ghost clone of his hardware.

RAID 0 is only worth while if you change your OS?Program paritition all the time, and also if you cannot afford to spend three hours or so restoring a back-up and installing the software you put on the machine since the last clone.

RAID 0 will provide no protection at all in the case of a buggy program or virus trashing your system, since the mirrored disk will be trashed in real time as well. I would say backing up all your user data to a second hard drive as well as to removeable media and a network drive, and keeping clones of teh OS/Program Files partition is better for the average user.

Stephen Jones
Friday, January 02, 2004

> Moreover the average user should be backing up his data every day

There *is* no simple solution for Joe User.

Automatic cold-copying of data to a second, non-RAIDed disk is the only one that comes close, and it is not built-in.

It's related to the islands of data idea in one of my previous posts. Computer administration is really too difficult and/or tedious for most folks. If bandwidth was sufficient, your service provider could backup your changes automatically and allow you a revert capabiliity; they would assume all the hassles of data storage.

However, it's not likely to be that way for several years at least, and so we'll stumble along with hugely complex OSes with carefully crafted interfaces and cajoling users (or their relatives and friends) into being their own sysadmins.

Portabella
Friday, January 02, 2004

To use a Joelism, I'd say RAID is another Leaky Abstraction.

Portabella
Friday, January 02, 2004

---"Automatic cold-copying of data to a second, non-RAIDed disk is the only one that comes close, and it is not built-in."----

Absolutely correct; what is worse is that having a separate data partition is not built in, in fact I believe MS would have a different tariff for OEM Windows for anybody that did it. And the restore CD's that come with laptops, and presumably desktops, wipe out any partitions you have made; that is to say they don't restore the system partition to factory state, they restore the whole disk.

REally by Joe User I mean Joe Expert-User; few other people have a chance.

You would think however that the OEM's might consider running a batch file with their setup that would suggest the user copy his default documents and email files to a CD using Windows XP backup.

Stephen Jones
Friday, January 02, 2004

"Given Philo's configuration, it will only set you back the cost of a single hard disk."

I don't think it's the cost that is being questioned, but rather the implication that RAID protects data -- RAID primarily protects uptime rather than data. If uptime isn't as important, and say performance is even more important, then you can use that extra disk in a performance striped set.

"Which is more likely to cause you to lose data?"

As mentioned, RAID doesn't fully protect data - any number of things can happen on a perfectly operating RAID array that will lead to the unrecoverable loss of data (such as someone busting into your house/office and carrying away your RAID away, fire, trojan, accidents, water damage, etc). I personally consider the likelihood of those other factors to be far more common than actual hardware failures.

So given this, regular backups are critical. So if you have regular backups, what has RAID bought you? Well it improves uptime if indeed a disk device fails -- you don't need to run a restore (and to be fair you will likely save a backup interval worth of data).

Dennis Forbes
Friday, January 02, 2004

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